Portland Coastal Marathon 10K vs Bath & Bristol Railway Races 10K

Name: Portland Coastal Marathon 10K vs Bath & Bristol Railway Races 10K comparison data
Creator: raceindex.org

Portland Coastal Marathon 10K or Bath & Bristol Railway Races 10K — which comes out ahead?

Bath & Bristol Railway Races 10K has the stronger available profile on flat grade share, course flatness and conditions.

Route comparison snapshot

Portland Coastal Marathon 10K

Mapped route: Held
Elevation profile: Held
course flatness: 4.8%
flat grade share: 39.6%
lower ascent: 207 m
climbing density: 20.7 m/km
net elevation: -0 m
maximum grade: 22.0%

Bath & Bristol Railway Races 10K

Mapped route: Held
Elevation profile: Held
course flatness: 0.1% Favoured
flat grade share: 99.3% Favoured
lower ascent: 7 m
climbing density: 0.7 m/km
net elevation: 1 m
maximum grade: 2.6%

Head-to-head comparison
Metric	Portland Coastal Marathon 10K	Bath & Bristol Railway Races 10K
Flat grade share	39.6%	99.3% ✓
GAP factor (% slower than flat)	4.8%	0.1% ✓
Uphill share	31.2%	0.3%
Steep-up share	11.5%	0.0%
Downhill share	29.2%	0.4%
Total ascent (m)	207 m	7 m
Climbing density (m/km)	20.7 m/km	0.7 m/km
Longest climb length (m)	840 m	400 m
Longest climb gain (m)	85 m	3 m
Longest climb average grade	10.1%	0.7%
Total descent (m)	208 m	6 m
Net elevation (m)	-0 m	1 m
Max absolute grade	22.0%	2.6%
Start elevation (m)	-0 m	18 m
Finish elevation (m)	-0 m	19 m
Value	Unavailable	84/100
Scenic score	87/100 ✓	83/100
Conditions	78/100	81/100 ✓
Entry fee (GBP)	Unavailable	£32
Lowest modelled true cost (GBP)	Unavailable	£162

Only metrics available for at least one side are shown. A ✓ marks the better value for each metric (higher-is-better aware). Scores are out of 100 when available. Ascent, climbing density, max absolute grade and median finish describe course or field context and are not marked as better or worse.

Race facts that change the decision

Race facts comparison
Fact	Portland Coastal Marathon 10K	Bath & Bristol Railway Races 10K
Schedule	Exact race date not confirmed. Event weekend starts 2027-02-14 (legacy event-level date).	Exact race date not confirmed. Event weekend starts 2026-10-11 (legacy event-level date).
Location	Portland, South West	Bath, South West
Actual distance	10 km	10 km
raceindex.org mapped route held	Held	Held
raceindex.org elevation profile held	Held	Held
Course type	Laps	Out And Back
Surface	Coastal trail on the South West Coast Path (exposed limestone peninsula terrain).	Essentially 100% tarmac, aside from a small amount of grass at the start and finish
Terrain	Trail	Trail
Scenery	Island, Coastal, Waterfront, City, Historic	Riverside, Countryside, Historic, City, Parkland
Atmosphere	Scenic Tour, Wilderness	Scenic Tour
Total ascent	207 m	7 m
Climbing density	20.7 m/km	0.7 m/km
Total descent	208 m	6 m
Net elevation	-0 m	1 m
Max absolute grade	22.0%	2.6%
Flat grade share	39.6%	99.3%
GAP factor	4.8%	0.1%
Entry model	Open	Open
Entry fee	Unavailable	£32
Lowest modelled true cost	Unavailable	£162
Cost model origin	Unavailable	National Average
Measured course	No	Yes

Schedule

Portland Coastal Marathon 10K: Exact race date not confirmed. Event weekend starts 2027-02-14 (legacy event-level date).
Bath & Bristol Railway Races 10K: Exact race date not confirmed. Event weekend starts 2026-10-11 (legacy event-level date).

Location

Portland Coastal Marathon 10K: Portland, South West
Bath & Bristol Railway Races 10K: Bath, South West

Actual distance

Portland Coastal Marathon 10K: 10 km
Bath & Bristol Railway Races 10K: 10 km

raceindex.org mapped route held

Portland Coastal Marathon 10K: Held
Bath & Bristol Railway Races 10K: Held

raceindex.org elevation profile held

Portland Coastal Marathon 10K: Held
Bath & Bristol Railway Races 10K: Held

Course type

Portland Coastal Marathon 10K: Laps
Bath & Bristol Railway Races 10K: Out And Back

Surface

Portland Coastal Marathon 10K: Coastal trail on the South West Coast Path (exposed limestone peninsula terrain).
Bath & Bristol Railway Races 10K: Essentially 100% tarmac, aside from a small amount of grass at the start and finish

Terrain

Portland Coastal Marathon 10K: Trail
Bath & Bristol Railway Races 10K: Trail

Scenery

Portland Coastal Marathon 10K: Island, Coastal, Waterfront, City, Historic
Bath & Bristol Railway Races 10K: Riverside, Countryside, Historic, City, Parkland

Atmosphere

Portland Coastal Marathon 10K: Scenic Tour, Wilderness
Bath & Bristol Railway Races 10K: Scenic Tour

Total ascent

Portland Coastal Marathon 10K: 207 m
Bath & Bristol Railway Races 10K: 7 m

Climbing density

Portland Coastal Marathon 10K: 20.7 m/km
Bath & Bristol Railway Races 10K: 0.7 m/km

Total descent

Portland Coastal Marathon 10K: 208 m
Bath & Bristol Railway Races 10K: 6 m

Net elevation

Portland Coastal Marathon 10K: -0 m
Bath & Bristol Railway Races 10K: 1 m

Max absolute grade

Portland Coastal Marathon 10K: 22.0%
Bath & Bristol Railway Races 10K: 2.6%

Flat grade share

Portland Coastal Marathon 10K: 39.6%
Bath & Bristol Railway Races 10K: 99.3%

GAP factor

Portland Coastal Marathon 10K: 4.8%
Bath & Bristol Railway Races 10K: 0.1%

Entry model

Portland Coastal Marathon 10K: Open
Bath & Bristol Railway Races 10K: Open

Entry fee

Portland Coastal Marathon 10K: Unavailable
Bath & Bristol Railway Races 10K: £32

Lowest modelled true cost

Portland Coastal Marathon 10K: Unavailable
Bath & Bristol Railway Races 10K: £162

Cost model origin

Portland Coastal Marathon 10K: Unavailable
Bath & Bristol Railway Races 10K: National Average

Measured course

Portland Coastal Marathon 10K: No
Bath & Bristol Railway Races 10K: Yes

Facts are shown only when they exist in the sourced race record; Not held means no sourced value is held for that race.

Common questions

Which is flatter, Portland Coastal Marathon 10K or Bath & Bristol Railway Races 10K?

Bath & Bristol Railway Races 10K has the lower GAP factor, making it the flatter course on our route model and more favourable on gradient alone.

Read the full pages

How figures are calculated →

How we calculated this

Published facts and derived model outputs on this page are tied to stored sources or a published, version-locked methodology. We show the provenance so runners, coaches and organisers can check it. Data on this page is current as of 2026-08-17.

Derived numbers use scoring-methodology-v1.0.

Sources used on this page (4)

Layer E archive-api.open-meteo.com
Layer B src_derived
Layer A bustinskintriathlonclub.clubtrac.co.uk · last check inconclusive on 2026-07-27
Layer A relishrunningraces.com · last check inconclusive on 2026-09-17

Read the full methodology →

Portland Coastal Marathon 10K or Bath & Bristol Railway Races 10K — which comes out ahead?

Route comparison snapshot

Portland Coastal Marathon 10K

Bath & Bristol Railway Races 10K

Flat grade share

GAP factor (% slower than flat)

Uphill share

Steep-up share

Downhill share

Total ascent (m)

Climbing density (m/km)

Longest climb length (m)

Longest climb gain (m)

Longest climb average grade

Total descent (m)

Net elevation (m)

Max absolute grade

Start elevation (m)

Finish elevation (m)

Value

Scenic score

Conditions

Entry fee (GBP)

Lowest modelled true cost (GBP)

Race facts that change the decision

Schedule

Location

Actual distance

raceindex.org mapped route held

raceindex.org elevation profile held

Course type

Surface

Terrain

Scenery

Atmosphere

Total ascent

Climbing density

Total descent

Net elevation

Max absolute grade

Flat grade share

GAP factor

Entry model

Entry fee

Lowest modelled true cost

Cost model origin

Measured course

Common questions

Which is flatter, Portland Coastal Marathon 10K or Bath & Bristol Railway Races 10K?

Read the full pages